JPS6132569B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an inner flame cylinder found in oil stoves, etc.
This relates to a multiplex gas combustor that has an outer flame tube with a red-hot part at the top and an outer tube with a heat-transmitting material such as heat-resistant glass placed on the outside, which are arranged concentrically to improve the flow of combustion gas. This allows for uniform red heat.

Until now, we have considered practical application with the upper parts of the inner and outer flame tubes closed (a) or opened (b) as shown in FIGS. 4a and 4b. Although each of these has its own characteristics, they also have drawbacks. In other words, in case a, the yellow flame characteristics and the CO/CO ₂ characteristics during ignition are good, but the gas burned between the inner and outer flame tubes and the gas that cannot be burned concentrates at the top of the outer flame tube, increasing the pressure and causing a thin flame below.
At the boundary with A , there is a point C where there is no flame or where the flame is very thin. This is thought to be due to the pressure gradient between the inner and outer flame cylinders, which tends to cause black band-like red heat unevenness, and also becomes a place where coco gas is generated when the combustion amount is reduced. In addition, the flame thickness in the upper high-pressure section becomes extremely thick, and the red-hot B temperature decreases. In addition, when the space between the inner and outer cylinders is open as shown in figure b, the uniformity is good and there is no unnatural pressure gradient, but flames occur between the inner and outer cylinders and D
In addition, yellow flame is likely to occur between the inner and outer flame cylinders, and the CO at the time of ignition is
It had drawbacks such as slightly poor characteristics.

The present invention aims to alleviate the above drawbacks and take advantage of its characteristics by considering the pressure balance between the inner and outer flame cylinders, and will be explained based on the drawings.

In FIGS. 1 and 2, reference numeral 1 is a burner, which is comprised of a nozzle 2 that regulates the amount of gas and a plurality of jet ports 3 that uniformly jet the gas, supplying gaseous fuel. 4 and 7 are an inner flame tube and an outer flame tube having a large number of small holes;
It is placed concentrically on the burner 1 and has combustion holes 5 and 8 in the upper part and premixing holes 6 and 9 in the lower part. Here, the lowest stage of the combustion holes 8 of the outer flame tube 7 is provided with a convex portion 10 that projects in the outer circumferential direction.
In the inner flame tube 4, the combustion holes 5 are located at least one or two steps higher than the lowest stage of the combustion holes 8 in the outer flame tube. Reference numeral 11 denotes a heat-resistant heat transmitting body provided opposite to the burning section, that is, the red-hot section of the outer flame tube, and is placed on the outer tube 12, provided concentrically with the inner and outer flame tubes, and held by known means. . Reference numeral 13 denotes an inner and outer flame tube cap that closes the upper part of the inner flame tube 4 and also closes the upper part of the outer flame tube 7, and as shown in FIG.
A notch-like opening 17 is formed between the two, and the protrusion 16 is placed on the outer flame tube 7, and several cut-outs 15 abut against the inner periphery of the outer flame tube, and the true shape of the outer flame tube is formed. By inserting the stepped portion 14 into the inner flame tube, the roundness of the inner flame tube 4 is maintained and concentricity is maintained. This opening 17 does not need to be a cutout hole, but should be provided on the outer flame cylinder side.

In the above structure, gas is uniformly ejected from the ejection port 3 of the burner 1 between the inner and outer flame cylinders via the nozzle 2, and rises upward while mixing with air from the small holes. At this time, it is ignited using a known ignition method. The flame is the inner flame tube 4
The combustion part pores 5 and the lower part of the combustion part of the outer flame tube 7 are formed. Then, a red-hot part spreads upward so that the flame surrounds the outer flame cylinder combustion part, and radiant heat is released through the heat transmitting body 11.

At this time, the convex portion at the bottom of the outer flame cylinder combustion section increases the amount of gas ejected from the bottom, promotes the formation of flame A in FIG. 4, and contributes to the ignition rise and uniform red heat. on the other hand,
The gas supplied between the inner and outer flame tubes is partially combusted in the combustion holes 5 by the air from the combustion holes 5 of the inner flame tube 4.
A part of it is pushed out from the outer flame tube combustion part pores 8 by the pressure and burns on the surface of the outer flame tube 7, and the remaining gas and the combustion exhaust gas produced in the inner flame tube air holes 5 rise along the inner flame tube 4. This mixed combustion gas hits the cap 13, and part of it is discharged through the cutout hole 17 and the rest is discharged from the upper outer periphery of the outer flame tube 7. That is, as shown in Fig. 4A, a thick flame zone is generated over a wide area at the top of the outer flame tube due to the back pressure from the completely closed upper part, but due to the opening 17, the flame on the outer periphery of the outer flame tube is suppressed as shown in Fig. 4C. The thickness is made uniform. As a result, uniform heating of the outer flame cylinder 7 is maintained up to the upper part, and uniform red heat is obtained. At this time, the change in red heat due to the state of flame formation due to the ratio of openings varies depending on the amount of combustion, the ratio of openings of pores in the inner and outer flame cylinders, the gap between each cylinder, etc., but the change under the conditions shown in Figure 3 The upper cross-sectional area between the inner and outer flame tubes is 14~
If it is 15% or more, a noticeable change in the flow will be recognized. Moreover, if it is 25% or more, the effect on red heat will be small, and if the openings are large, the occurrence of yellow fire as described above will be observed. Therefore, it is practical to use 14 to 15% or more within the range where yellow flame does not occur. (Generally speaking, 20-35% is best, depending on conditions, and 60% is best.
If it exceeds %, there is a risk of yellow fire. ) In this way, the present invention is able to equalize the red heat in the vertical direction of the outer flame tube, and also absorb differences in gas quality by changing the area of the partially cut-out opening.
Furthermore, since the partially cut-out opening is provided on the outer flame cylinder side of the closed part, the flow of high temperature combustion gas is formed up to the upper part of the outer flame cylinder side, thereby ensuring the uniformity of the red heat.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a combustion section according to an embodiment of the present invention, Fig. 2 is an enlarged view of its main parts, Fig. 3 is a characteristic diagram showing the effect of the cap opening ratio, and Figs. Fig. 4c is a diagram showing the form of flame caused by the combustor of the present invention. 1... Burner, 4... Inner flame tube, 7... Outer flame tube,
11... Heat transmitting body, 12... Outer tube, 13... Inner and outer flame tube cap, 17... Opening hole.

Claims (1)

[Claims] 1. An inner flame tube and an outer flame tube having a plurality of small holes are arranged concentrically, and an outer tube with a heat-resistant heat transmitting material placed on the outer periphery thereof is provided concentrically. A combustor characterized in that the upper portions of the inner and outer flame tubes are closed, and a partially cut-out opening is provided in the closed portion between the inner and outer flame tubes from the outer flame tube side. 2 The aperture of the closed part between the inner and outer flame tubes is an abbreviation of the area between the inner and outer flame tubes.
The combustor according to claim 1, wherein the combustor has a ratio of 14% or more.